Process and mould for thermoforming containers

ABSTRACT

The present invention relates to a method ol manufacturing water-soluble containers using a horizontal intermittent motion thermolorming machine which comprises the steps of: a) locating a first water-soluble film overa mould, said mould containing a plurality of pocket forming cavities, defined by side walls and a base, in a 2-dimensional array, each cavity being surrounded by a planar surface of the mould on all sides in which the shortest dimension of the planar surface between two adjacent cavities is at least 3 mm and between an edge of the mould and the closest cavity is at least 1.5 mm; b) thermoforming the first film to produce a plurality of pockets; c) at least partially filling the pockets with a composition; and d) sealing the plurality ol the at least partially filled pockets. The cavities are positioned in the array such that there are a plurality of continuous strips of uninterrupted planar surface of the mould from a leading to a trailing edge ol the mould, for receiving support means fitted to the machine for supporting the film.

The present invention relates to a method of manufacturing water-solublecontainers and a mould for use therein.

It is known to package chemical compositions which may be of a hazardousor irritant nature in water soluble or water dispersible materials suchas films. The package can simply be added to water in order to dissolveor disperse the contents of the package into the water.

For example, WO 89/12587 discloses a package which comprises an envelopeof a water soluble or water dispersible material which comprises aflexible wall and a water-soluble or water-dispersible heat seal. Thepackage may contain an organic liquid comprising, for example, apesticide, fungicide, insecticide or herbicide.

It is also known to package detergents in water-soluble orwater-dispersible containers. For example, WO 94/14941 discloses awater-soluble or water-dispersible capsule containing an aqueousdishwasher detergent. The capsule is made of gelatin.

CA-A-1,112,534 discloses a packet made of a water-soluble material infilm form enclosing within it a paste-form, automaticdishwasher-compatible detergent composition. The water-soluble materialmay be, for example, polyvinyl alcohol, polyethylene oxide or methylcellulose. Example 1 illustrates an embodiment wherein a poly(vinylalcohol) (PVOH) film is made into a 5 cm square packet by heat sealingits edges, and the packet is filled with a composition which contains8.5 wt.% water.

In fields such as detergents for domestic use, an attractive appearancefor an article is extremely desirable. However in the prior art, such asthat described above, a bag is simply formed from a single sheet ofwater-soluble film. The film is folded and the edges heat-sealed to formthe bag. The bag is then filled and heat-sealed. This produces a ratherflat, limp envelope containing the product. Furthermore there may be alack of uniformity between different bags because of their flexiblenature.

We have discovered that this type of product is not deemed to beattractive by an average consumer.

It is known to form water-soluble containers by thermoforming awater-soluble material. For example, WO 92/17382 discloses a packagecontaining an agrochemical such as a pesticide comprising a first sheetof non-planar water-soluble or water-dispersible material and a secondsheet of water-soluble or water-dispersible material superposed on thefirst sheet and sealed to it by a continuous closed water-soluble orwater-dispersible seal along a continuous region of the superposedsheets. It is stated to be advantageous to ensure that the packageproduced is evacuated of air or the contents are under reduced pressureto provide increased resistance to shock. Furthermore, when the packagecontains a liquid, the liquid must be an organic liquid which must bereasonably dry and typically contains less than 2 to 3% of water toensure that it does not attack the water-soluble package and causeleakage.

EP-A-654,418 describes self-standing flexible pouches which may contain,for example, liquid detergent compositions for refilling othercontainers. In order to avoid folding of the pouch, which can lead tocracking and leakage, the bag is inflated before it is sealed.

In order to improve the strength of packages containing liquids, it isalso known to provide the package with residual inflatability. Thus, forexample, EP-A-524,721 describes a water-soluble package which contains aliquid, wherein the package is inflatable to a volume which is greaterthan the initial volume of the package. Thus the package is filled toless than its complete capacity, and the unused capacity may bepartially, but not totally, filled with a gas such as air. The unusedcapacity which does not contain gas provides the residual inflatability.

We have now surprisingly discovered a water-soluble container whichcontains a liquid composition can be given an attractivethree-dimensional appearance by using a thermoforming technique, such asthat disclosed in WO 92/17382, on a PVOH film and ensuring that theliquid composition has a reasonably large water content of at least 3wt% free water, based on the weight of the aqueous composition.Immediately after the containers are prepared, they have a limp,unattractive appearance. However, after storage for a short while, forexample, from a few minutes to a few hours, they develop a moreattractive three-dimensional appearance, and also appear to look fuller.They can also be said to have a “puffed-up” appearance. Although notbound by this theory, it is believed that the water in the aqueouscomposition shrinks the PVOH film around the liquid composition toprovide the attractive appearance. In other words the PVOH film attemptsto recover its original shape when contacted with the aqueouscomposition.

In our co-pending application entitled “Improvements in or Relating toAqueous Compositions” we describe a process for producing a container asdefined above which comprises the steps of:

b) filling the pocket with the aqueous composition;

c) placing a second PVOH film on top of the filled pocket; and

d) sealing the first film and second film together.

The method of forming the container is similar to the process describedin WO 92/17382. A first PVOH film is initially thermoformed into a mouldto produce a non-planar sheet containing a pocket, such as a recess,which is able to retain the aqueous composition. The pocket is generallybounded by a flange, which is preferably substantially planar. Thepocket may have internal barrier layers as described in, for example, WO93/08095. The pocket is then filled with the aqueous composition, and asecond PVOH film is placed on the flange and across the pocket. Thesecond PVOH film may or may not be thermoformed. The pocket may becompletely filled, or only partly filled, for example to leave an airspace of from 2 to 20%, especially from 5 to 10%, of the volume of thecontainer immediately after it is formed. Partial filling may reduce therisk of rupture of the container if it is subjected to shock and reducethe risk of leakage if the container is subjected to high temperatures.

The films are then sealed together, for example by heat sealing acrossthe flange. A suitable heat sealing temperature is, for example, 120° C.to 195° C., for example 140° C. to 150° C. A suitable sealing pressureis, for example, from 250 kPa to 800 kPa. Examples of sealing pressuresare 276 kPa to 552 kPa (40 p.s.i. to 80 p.s.i.), especially 345 kPa to483 kPa (50 p.s.i. to 70 p.s.i.) or 400 kPa to 800 kPa (4 to 8 bar),especially 500 kPa to 700 kPa (5 to 7 bar) depending on the heat sealingmachine used. Suitable sealing dwell times are at least 0.4 seconds, forexample 0.4 to 2.5 seconds. Other methods of sealing the films togethermay be used,

plate, insert bonding, fraction sealing or spin welding. An adhesivesuch as water or an aqueous solution of PVOH may also be used. Theadhesive can be applied to the films by spraying, transfer coating,roller coating or otherwise coating, or the films can be passed througha mist of the adhesive. The seal desirably is also water-soluble.

It is, however, extremely difficult to manufacture products using PVOHand other materials having similar physical characteristics, partlybecause of their hygroscopic nature, but mainly due to the fact that thematerial is very soft and floppy, making it extremely difficult tohandle and cut. In most thermoforming, vacuum forming or other similarforming processes, the films used have a degree of strength andrigidity. Thus friction drives are generally, although not exclusively,used to support the films and to transport them through the machineduring the process. PVOH and similar films do not have this strength orrigidity and would stretch, thin and tear if subjected to such handling.

Furthermore, thermo- and other such forming processes impose asignificant amount of drawing and stretching of the material. As suchthe known method of thermoforming using PVOH materials utilises a singlemould for each moulded product, with each PVOH film placed manually overeach mould. This means that the amount of material available fordeforming is greater, but it is a very labour intensive, slow andtherefore costly process to achieve the manufacture of this type ofproduct.

We have discovered that standard horizontal intermittent motionthermoforming machines, such as those supplied by Multivac, Doyen andTiromat, can be used to produce thermoformed containers from PVOH andfilms of a

particular to the drive system, in order to run such films at normalproduction speeds.

It is therefore an object of the present invention to provide animprovement in the process for manufacturing such containers, to enablea plurality of water-soluble containers to be formed simultaneously. Afurther objective is to provide a tool for use in a process forproducing a plurality of water-soluble containers made from PVOH orother films of a similar physical nature or the like, at each stroke ofan horizontal intermittent motion thermoforming machine. Yet anotherobjective is to provide an improved process for producing multiplecontainers on a production scale.

The invention therefore provides a process for producing a water-solublecontainer using a horizontal intermittent motion thermoforming machinewhich comprises the steps of:

a) locating a first water-soluble film over a mould, said mouldcontaining a plurality of pocket forming cavities, defined by side wallsand a base, in a 2-dimensional array, each cavity being surrounded by aplanar surface of the mould on all sides in which the shortest dimensionof the planar surface between two adjacent cavities is at least 3 mm andbetween an edge of the mould and the closest cavity is at least 1.5 mm;

b) thermoforming the first film to produce a plurality of pockets;

c) at least partially filling the pockets with a composition; and

d) sealing the plurality of the at least partially plurality ofcontinuous strips of uninterrupted planar surface of the mould from aleading to a trailing edge of the mould, for receiving support meansfitted to the machine for supporting the film.

The invention further provides a mould for use in a thermoformingprocess for manufacturing water-soluble containers from water-solublefilms, in which said mould contains a plurality of pocket formingcavities, defined by side walls and a base, in a 2-dimensional array,each cavity being surrounded by a planar surface of the mould on allsides in which the shortest dimension of the planar surface between twoadjacent cavities is at least 3mm and between an edge of the mould andthe closest cavity is at least 1.5 mm, and in which the cavities arepositioned in the array such that there are a plurality of continuousstrips of uninterrupted planar surface of the mould from a leading to atrailing edge of the mould.

The invention will now be described, in further detail, by way ofexample only, with reference to and as shown in the accompanyingdrawings in which:-

FIG. 1 is an end elevation of a mould used in the present invention;

FIG. 2 is a side sectional elevation of the mould of FIG. 1 on the lineI-I;

FIGS. 3 to 5 are respectively plan views and cross sectional sideelevations of a section of the mould of FIG. 1 showing the dimensions ofthe cavities;

FIG. 6 is a plan view of the mould of FIG. 1; and

FIG. 8 shows support rails supporting a web of material on a horizontalintermittent thermoforming machine.

FIGS. 1 and 2 show a mould 10 used for thermoforming a plurality ofcontainers from PVOH or films having similar physical characteristics ona horizontal intermittent thermoforming machine comprising a series ofstations as shown in FIG. 7. These are the forming area 30, at which thefilm 31 is supplied from a reel to the moulds 10 and where the firstthermoforming step takes place to form pockets; the filling station 32,at which the pockets are filled; the sealing station 33, to which afurther film 34 is supplied to seal the pockets; the cooling station 35;and the cutting station 36 where the sealed containers are separatedfrom each other by shear knives 38.

Each mould 10 comprises a 2-dimensional array of pocket forming cavities11. Although the Figures illustrate a regular array of 6×7 cavities 11to form 42 containers simultaneously, the number and relativepositioning of the cavities 11 may be varied. Essentially the surfacedimensions of the mould are determined by the width and draw of themachine on which it is to be used. The best arrangement of theindividual cavities 11 is determined according to the followingconsiderations.

Each cavity 11 must be surrounded by a planar surface 18 on all sides,to allow for subsequent sealing of the second film to the first films.This dimension should be at least 1.5 mm, but is preferably in the rangeof 2 mm to 5 mm. Thus the distance between any cavity and the edge ofthe mould 10 is at least 1.5 mm and the distance between any twocavities 11 is at least 3 mm. The maximum distance is obviouslydetermined by the size

As the materials used are very flexible, the web of film tends to sag.In order to enable all of the cavities 11 to be filled, support meansmust be fitted to the machine, from the end of the thermoforming stationto the start of the filling station, and also preferably to the cuttingstation 36, to support the web of film. The support means may beprovided by rails, bars, filaments, wires, rope, cable or the like. Mostpreferred are wires or rails. Where rails 1 are used, as shown in FIG.7, the leading ends of the rails may have a smooth cam surface 2 forlifting the web. The support means can be intermittent or, morepreferably, continuous.

FIG. 8 shows how the web is drawn down from the thermoforming station bybeing held by grippers 3 which are pulled apart to provide some tensionin the web. Too much tension will displace the thermoformed pockets.However, not enough tension is provided so that the web remains flat forfilling. The support rails 1 maintiain the web as a substantially flatsurface.This places an extra constraint on the arrangement of thecavities within the space available i.e. there must be clear channels 21(see arrows Z on FIG. 6) through the pattern of cavities 11 from theleading edge of the mould 10 to the trailing edge. It is preferred thatthese channels 21 are available between each cavity 11 (across the webi.e. on the leading edge), but this is not essential, depending on thenumber of cavities 11 across the leading edge. At least every othercavity should be supported.

Located in the mould 10 beneath the cavities 11 are air channels 15,which communicate with the cavities 11 via air bores 16. The number andpositioning of the air bores 15 has an effect on how the film is drawninto the cavities 11 during the thermoforming process, and

configuration of the cavities 11 used. In particular they must bedesigned and arranged to effect the most even deformation of the filminto the cavities 11. In a preferred embodiment the air bores 15 arelocated in the regions where the end and side walls 12, 13 of thecavities 11 join the cavity base 14. The holes are preferably of 0.1 mmto 1 mm diameter and more preferably 0.4 mm to 0.5 mm. Vacuum releasebores 17 are drilled in the cavity bases 14.

The shape of the cavities 11 is dictated partly by the intended use ofthe containers, but also by the processing constraints. A particularlyconvenient shape for an automatic dishwasher composition is illustratedin FIG. 3 to 5. The dimensions of the cavities are determined by therequired fill volume of the containers and any constraints resultingfrom the intended use of the containers. For example, if the containersare to be used as refill sachets for a trigger spray, the width of thecontainers, and therefore the cavities is determined by the diameter ofthe spray bottle neck. If the containers are to be used for a dishwasherproduct, all three dimensions are determined by the dispenser into whichthe containers will eventually be placed.

One particularly suitable embodiment which we have found for adishwasher product has a rectangular cavity mouth, the dimensions ofwhich are 29 mm ×39 mm, with rounded corners, having a radius R₁ of,preferably, 10 mm.

The depth of the cavities depends partly on the area of the cavitymouth, to ensure that the film, can be drawn down without over thinningand tearing. This can also be affected by the area of film availablebetween adjacent cavities 11. Referring to FIG. 6, the upper surface 18of the mould 10 can clearly be seen. The gaps between the cavities 11are marked as dimensions

preferably about 1:1. X and Y are desirably from 5 to 13 mm, preferably7 to 12 mm, preferably about 10 mm. The preferred depth is in the rangeof 10 to 80% of the shortest dimension of the cavity mouth, and morepreferably in the range of 40 to 60 %. A preferred depth of the cavities11 where the mouth of the cavities 11 is 29 mm by 39 mm is 16 mm.

The corners 19 formed where the end and side walls 12,13 of the cavities11 join the cavity base 14, are preferably radiussed to avoid overthinning or tearing of the film, as it is drawn down the side walls 13and the corners 19. The corners 19 preferably have a radius R₂ and R₃ ofbetween 8 mm and 10 mm.

The cavity base 14 may be planar or rounded. Especially where a greatercavity depth is used, such as 18 mm or 19 mm, it may be preferable tohave a rounded base 14 to prevent regions of thicker material from beingdrawn directly downward to the centre of the base 14. A suitable radiusfor the base 14, in particular where the cavity depth is 18 mm, is 20mm. The use of a rounded base 14 means that the positioning anddirection of the air bores 16 may be different from those used withflat-bottomed cavities 11. This changes the way in which the film isdrawn into the cavities 11.

The edges 20, where the cavity end and side walls 12,13 join the uppersurface 18 of the mould 10, are preferably rounded to allow for a smoothmovement of the film over the edges 20 during the thermoforming process,to minimise the risk of the film snagging or tearing. The radius R₄ ispreferably small, e.g. 1 mm, as it is difficult to fill this area of thecavities 11 without risk of fouling the sealing area.

Another dimension which must be carefully controlled

For cavities of the dimensions given above, it is preferred that thespacing between the cavities lies in the range of 9 mm to 16 mm.

The draft angle of the side walls 12, 13 is preferably 3° to 5° toassist in the release of the containers. However, for certain very softmaterials, such as PVOH, draft angles may not be necessary.

The sizing of the mould 10, incorporating an array of cavities 11 inthis manner, enables the film to be supported. The width of the web offilm is determined by the width of the machine in which the mould isfitted. The mould is designed to fit the width of the machine with asuitable “overhang” of film, which can be used for transporting thefilm. It is suggested that small clips or grippers attached to aplurality of driven chains would enable the films to be transportedappropriately. The grippers preferably toe-out to provide tension as theweb of film moves through the machine.

A first PVOH film is thus positioned over the mould 10 and thermoformedin a known manner to form a plurality of pockets. The pockets are thenfilled with an aqueous or other composition and a second film broughtinto position over the plurality of pockets. The second film may be thesame as the first film or another material and is heat, or otherwisesealed, to the parts of the first film remaining on the upper surface 18of the mould, as described previously.

The filled containers may then be separated from each other.Alternatively, they may be left conjoined and, for example, perforationsprovided between the individual containers so that they can be separatedeasily at a later stage, for example by a consumer. If the containersare separated, the flanges may be left in

dimensional appearance. Generally the flanges remaining should be assmall as possible for aesthetic purposes while bearing in mind that someflange is required to ensure the two films remain adhered to each other.A flange having a width of 1 mm to 10 mm is desirable, preferably 1.5 mmto 6 mm, most preferably about 5 mm.

For containers of compositions having a high water content, thecontainers may then be left for a while to attain their attractiveappearance, or may be immediately packaged into boxes for retail sale,and left to attain their attractive appearance in the boxes. Thecontainers may themselves be packaged in outer containers if desired,for example non-water soluble containers which are removed before thewater-soluble containers are used.

If more than one film is used for the containers, the films may beidentical or different. The film may be partially or fully alcoholisedor hydrolysed, for example, it may be from 40 to 100%, preferably 70 to92%, more preferably about 88% or about 92%, alcoholised or hydrolysed,polyvinyl acetate film. The degree of hydrolysis is known to influencethe temperature at which the PVOH starts to dissolve in water. 88%hydrolysis corresponds to a film soluble in cold (i.e. room temperature)water, whereas 92% hydrolysis corresponds to a film soluble in warmwater. An example of a preferred PVOH is ethoxylated PVOH. The film maybe cast, blown or extruded. It may also be unorientated, mono-axiallyoriented or bi-axially oriented.

It is possible for suitable additives such as plasticisers, lubricantsand colouring agents to be added to the film. Components which modifythe properties of the polymer may also be added. Plasticisers aregenerally used in an amount of up to 20 wt%, for example, from 15 to 20wt%. Lubricants are generally used in an

on the total number of the composition used to form the film. Suitableplasticisers are, for example, pentaerythritols such asdepentaerythritol, sorbitol, mannitol, glycerine and glycols such asglycerol, ethylene glycol and polyethylene glycol. Solids such as talc,stearic acid, magnesium stearate, silicon dioxide, zince stearate orcolloidal silica may also be used.

It is also possible to include one or more particulate solids in thefilms in order to accelerate the rate of dissolution of the container.This solid may also be present in the contents of the container.Dissolution of the solid in water is sufficient to cause an accelerationin the break-up of the container, particularly if a gas is generated,when the physical agitation caused may, for example, result in thevirtually immediate release of the contents from the container. Examplesof such solids are alkali or alkaline earth metal, such as sodium,potassium, magnesium or calcium, bicarbonate or carbonate, in insolublein cold water at 20° C. and only become soluble example, acidicsubstances having carboxylic or sulfonic acid groups or salts thereof.Examples are cinnamic, tartaric, mandelic, fumaric, maleic, malic,palmoic, citric and naphthalene disulfonic acids.

The film is generally cold water (20° C.) soluble, but, depending on itsdegree of hydrolysis, may be insoluble in cold water at 20° C. and onlybecome soluble in warm water or hot water having a temperature of, forsoluble in cold water, or water at a temperature of up to say 35° C.,steps must be taken to ensure that an aqueous composition containedinside the container does not dissolve the film from the inside. Stepsmay be taken to treat the inside surface of the film, for example bycoating it with a semi-permeable or partial water barrier

or dissolve or disperse into microscopic particles when described inmore detail in EP-A-518,689 and WO 97/27743. taken to adapt thecomposition to ensure that it does not dissolve the film. For example,it has been found that ensuring the composition has a high ionicstrength or contains an agent which minimises water loss through thewalls of the container will prevent the composition from dissolving thePVOH film from the inside. This is described in more detail inEP-A-518,689 and WO 97/27743.

It is particularly important to avoid pinholes in the film through whichleakage of the contained composition may occur. It may therefore beappropriate to use a laminate of two or more layers of a different orthe same film, as pinholes are unlikely to coincide in two layers ofmaterial.

When first and second films are used to form the thickness of the secondfilm will generally be from 20 to generally have a thickness beforethermoforming of 20 to 500 μm, especially 70 to 400 μm, for example 70to 300 μm or 90 or 110 to 150 μm. The thickness of the second PVOH filmmay be less than that of the first film as the second film will notgenerally be thermoformed so localised thinning of the sheet will notoccur. The thickness of the second film will generally be from 20 to 150μm or 160 μm, preferably from 40 or 50 to 90 or 100 μm, more preferablyfrom 50 to 80 μm.

The films may be chosen, if desired, such that they have the samethickness before the first film is thermoformed, or have the samethickness after the first from 25 to 35 g, and a laundry composition mayweigh from composition which is encapsulated by a substantially constantthickness of film.

The containers of the present invention generally

use. For example, a dishwashing composition may weigh from 15 g to 20 g,a water-softening composition may weigh from 25 to 35 g, and a laundrycomposition may weigh from 10 to 40 g, especially 20 to 30 g or 30 to 40g.

The containers may have any shape achievable by thermoforming. Forexample they can take the form of a cylinder, cube or cuboid, i.e. arectangular parallelepiped whose faces are not all equal. In general,because the containers are not rigid, the sides are not planar, butrather are convex. If the container is formed from a thermoformed filmand a planar film, the seam between the two films will appear nearer oneface of the container rather than the other. Apart from the deformationof the container due to the shrinkage of the film discussed above,deformation may also occur at the stage of manufacture if desired. Forexample, if the pocket is filled with a gelled composition having aheight greater than that of the pocket, the second film will be deformedwhen placed on top of the pocket. A shaped sealing platen is required toachieve this effect.

In general the maximum dimension of the filled part of the container(excluding any flanges) is 5 cm. For example, a rounded cuboid containermay have a length of 1 to 5 cm, especially 3.5 to 4.5 cm, a width of 1.5to 3.5 cm, especially 2 to 3 cm, and a height of 1 to 2.5 cm, especially1 to 2 cm, and more especially 1.25 to 1.75 cm.

The container desirably contains an aqueous composition which is afabric care, surface care or dishwashing composition. Thus, for example,it may be a dishwashing, water-softening, laundry or detergentcomposition or a rinse aid. In this case the container is preferablysuitable for use in a domestic washing machine such as a laundry washingmachine or a dishwashing machine. The composition may also be a

concentrated refill composition, for example a trigger-type spray asused in domestic situations. Such a composition can simply be added towater already held in the spray container. Examples of surface carecompositions are those used to clean, treat or polish a surface.Suitable surfaces are, for example, household surfaces such as worktops,as well as surfaces of sanitary ware, such as sinks, basins andlavatories.

The composition preferably contains greater than 3 wt% free water basedon the weight of the aqueous composition, in order to ensure that thecontainer has an attractive appearance. The actual amount of waterpresent in the composition may be in excess of the amount of free water,since the total water content includes water of solvation and water heldwithin a gelled matrix. Free water can be determined by a standardloss-on-drying determination test carried out at 60° C. for 3 hours at200 mbar (20 kPa). Desirably the composition contains more than 10 wt%,15 wt%, 20 wt%, 25 wt% or 30 wt% total water, but desirably less than 80wt% total water, more desirably less than 70 wt%, 60 wt%, 50 wt% or 40wt% total water. It may, for example, contain from 30 to 65 wt% totalwater.

The remaining ingredients of the composition depend on the use of thecomposition. Thus, for example, the compositions may contain surfaceactive agents such as an anionic, nonionic, cationic, amphoteric orzwitterionic surface active agents or mixtures thereof.

Examples of anionic surfactants are straight-chained or branched alkylsulfates and alkyl polyalkoxylated sulfates, also known as alkyl ethersulfates. Such surfactants may be produced by the sulfation of higherC₈-C₂₀ fatty alcohols.

ROSO₃ ^(−M) ⁺wherein R is a linear C₈-C₂₀ hydrocarbyl group and M is awater-solubilising cation. Preferably R is C₁₀-C₁₆ alkyl, for exampleC₁₂-C₁₄, and M is alkali metal such as lithium, sodium or potassium.

Examples of secondary alkyl sulfate surfactants are those which have thesulfate moiety on a “backbone” of the molecule, for example those offormula:CH₂(CH₂)_(n)(CHOSO₃ ^(−M+) (CH) ₂)_(m)CH₃wherein m and n are independently 2 or more, the sum of m+n typicallybeing 6 to 20, for example 9 to 15, and M is a water-solubilising cationsuch as lithium, sodium or potassium.

Especially preferred secondary alkyl sulfates are the (2,3) alkylsulfate surfactants of formulae:CH₂(CH₂)_(x)(CHOSO₃−M+) CH₃ and CH₃ (CH₂)_(x)(CHOSO₃−M+) CH₂CH₃for the 2-sulfate and 3-sulfate, respectively. In these formulae x is atleast 4, for example 6 to 20, preferably 10 to 16. M is a cation, suchas an alkali metal, for example lithium, sodium or potassium. Examplesof alkoxylated alkyl sulfates are ethoxylated alkyl sulfates of theformula:RO(C₂H₄O)_(n)SO₃−M+wherein R is a C₈-C₂₀ alkyl group, preferably C₁₀-C₁₈ such

forming cation such as lithium, sodium, potassium, ammonium,alkylammonium or alkanolammonium. These compounds can provide especiallydesirable fabric cleaning performance benefits when used in combinationwith alkyl sulfates.

The alkyl sulfates and alkyl ether sulfates will generally be used inthe form of mixtures comprising varying alkyl chain lengths and, ifpresent, varying degrees of alkoxylation.

Other anionic surfactants which may be employed are salts of fattyacids, for example C₈-C₁₈ fatty acids, especially the sodium, potassiumor alkanolamine salts, and alkyl, for example C₈-C₁₈, benzenesulfonates.

Examples of nonionic surfactants are fatty acid alkoxylates, such asfatty acid ethoxylates, especially those of formula:R(C₂H₄O)_(n)OHwherein R is a straight or branched C₈-C₁₆ alkyl group, preferably aC₉-C₁₅, for example C₁₀-C₁₄ or C₁₂-C₁₄, alkyl group and n is at least 1,for example from 1 to 16, preferably 2 to 12, more preferably 3 to 10.

The alkoxylated fatty alcohol nonionic surfactant will frequently have ahydrophilic-lipophilic balance (HLB) which ranges from 3 to 17, morepreferably from 6 to 15, most preferably from 10 to 15.

Examples of fatty alcohol ethoxylates are those made from alcohols of 12to 15 carbon atoms and which contain about 7 moles of ethylene oxide.Such materials are commercially marketed under the trademarks Neodol25-7 and Neodol 23-6.5 by Shell Chemical Company. Other

about 5 moles of ethylene oxide; Neodol 23-9, an ethoxylated primaryC₁₂-C₁₃ alcohol having about 9 moles of ethylene oxide; and Neodol91-10, an ethoxylated C₉-C₁₁ primary alcohol having about 10 moles ofethylene oxide.

Alcohol ethoxylates of this type have also been marketed by ShellChemical Company under the Dobanol trademark. Dobanol 91-5 is anethoxylated C₉-C₁₁ fatty alcohol with an average of 5 moles ethyleneoxide and Dobanol 25-7 is an ethoxylated C₁₂-C₁₅ fatty alcohol with anaverage of 7 moles of ethylene oxide per mole of fatty alcohol.

Other examples of suitable ethoxylated alcohol nonionic surfactantsinclude Tergitol 15-S-7 and Tergitol 15-S-9, both of which are linearsecondary alcohol ethoxylates available from Union Carbide Corporation.Tergitol 15-S-7 is a mixed ethoxylated product of a C₁₁-C₁₅ linearsecondary alkanol with 7 moles of ethylene oxide and Tergitol 15-S-9 isthe same but with 9 moles of ethylene oxide.

Other suitable alcohol ethoxylated nonionic surfactants are Neodol45-11, which is a similar ethylene oxide condensation products of afatty alcohol having 14-15 carbon atoms and the number of ethylene oxidegroups per mole being about 11. Such products are also available fromShell Chemical Company.

Further nonionic surfactants are, for example, C₁₀-C₁₈ alkylpolyglycosides, such as C₁₂-C₁₆ alkyl polyglycosides, especially thepolyglucosides. These are especially useful when high foamingcompositions are desired. Further surfactants are polyhydroxy fatty acidamides, such as C₁₀-C₁₈ N-(3-methoxypropyl) glycamides and ethyleneoxide-propylene oxide block polymers of the Pluronic type.

Examples of cationic surfactants are those of the quaternary ammoniumtype. Examples of amphoteric surfactants are C₁₀-C₁₈ amine oxides andthe C₁₂-C₁₈ betaines and sulfobetaines.

The total content of surfactants in the composition is desirably 0.1 to95 wt%, especially 60 or 75 to 90 wt%.

The total content of surfactants in the laundry or detergent compositionis desirably 60 to 95 wt%, especially 75 to 90 wt%. Desirably,especially in a laundry composition, an anionic surfactant is present inan amount of 50 to 75 wt%, a nonionic surfactant is present in an amountof 5 to 20 wt%, and/or a cationic surfactant is present in an amount offrom 0 to 10 wt% and/or a amphoteric surfactant may be present in anamount of from 0 to 10 wt%. Desirably, in a dishwashing composition, theanionic surfactant is present in an amount of from 0.1 to 50 wt%, anon-ionic surfactant is present in an amount of 0.5 to 20 wt% and/or acationic surfactant is present in an amount of from 1 to 15 wt%. Theseamounts are based

On the solids content of the composition, i.e. excluding any water orsolvent which may be present.

The compositions, particularly when used as laundry washing ordishwashing compositions, may also comprise enzymes, such as protease,lipase, amylase, cellulase and peroxidase enzymes. Such enzymes arecommercially available and sold, for example, under the registered trademarks Esperese, Alcalase, Savinase, Termamyl, Lipolase and Celluzyme byNova Industries A/S and Maxatasc by International Biosynthetics, Inc.Desirably the enzymes are present in the composition in an amount offrom 0.5 to 3 wt%, especially 1 to 2 wt%.

Dishwasher compositions usually comprise a detergency builder. Suitablebuilders are alkali metal or ammonium phosphates, polyphosphates,phosphonates, polyphosphonates carbonates, bicarbonates borates,polyhydroxysulfonates, polyacetates, carboxylates and polycarboxylatessuch as citrates. The builder is desirably present in an amount of up to90 wt%, preferably 15 to 90 wt%, more preferably 15 to 75 wt%, relativeto the total content of the composition.

Further details of suitable components are given in, for example,EP-A-694,059, EP-A-518720 and WO 99/06522.

The compositions may, if desired, comprise a thickening agent or gellingagent. Suitable thickeners are polyacrylate polymers such as those soldunder the trade mark CARBOPOL, or the trade mark ACUSOL by Rohm and HaasCompany. Other suitable thickeners are xanthan gums. The thickener, ifpresent, is generally present in an amount of from 0.2 to 4 wt%,especially 0.5 to 2 wt%.

The compositions can also optionally comprise one or more additionalingredients. These include conventional detergent composition componentssuch as further surfactants, bleaches, bleach enhancing agents,builders, suds boosters or suds suppressors, anti-tarnish andanti-corrosion agents, organic solvents, co-solvents, phase stabilisers,emulsifying agents, preservatives, soil suspending agents, soil releaseagents, germicides, phosphates such as sodium tripolyphosphate orpotassium tripolyphosphate, pH adjusting agents or buffers, non-builderalkalinity sources, chelating agents, clays such as smectite clays,enzyme stabilizers, anti-limescale agents, colourants, dyes,hydrotropes, dye transfer inhibiting agents, brighteners and perfumes.If used, such optional ingredients will generally constitute no morethan 10 wt%, for example from 1 to 6 wt%, of the

The builders counteract the effects of calcium, or other ion, waterhardness encountered during laundering or bleaching use of thecompositions herein. Examples of such materials are citrate, succinate,malonate, carboxymethyl succinate, carboxylate, polycarboxylate andpolyacetyl carboxylate salts, for example with alkali metal or alkalineearth metal cations, or the corresponding free acids. Specific examplesare sodium, potassium and lithium salts of oxydisuccinic acid, melliticacid, benzene polycarboxylic acids, C₁₀-C₂₂ fatty acids and citric acid.Other examples are organic phosphonate type sequestering agents such asthose sold by Monsanto under the trade mark Dequest and alkyl hydroxyphosphonates. Citrate salts and C₁₂-C₁₈ fatty acid soaps are preferred.

Other suitable builders are polymers and copolymers known to havebuilder properties. For example, such materials include appropriatepolyacrylic acid, polymaleic acid, and polyacrylic/polymaleic andcopolymers and their salts, such as those sold by BASF under the trademark Sokalan.

The builders generally constitute from 0 to 3 wt%, more preferably from0.1 to 1 wt%, by weight of the compositions.

Compositions which comprise an enzyme may optionally contain materialswhich maintain the stability of the enzyme. Such enzyme stabilizersinclude, for example, polyols such as propylene glycol, boric acid andborax. Combinations of these enzyme stabilizers may also be employed. Ifutilized, the enzyme stabilizers generally constitute from 0.1 to 1 wt%of the compositions.

The compositions may optionally comprise materials which serve as phasestabilizers and/or co-solvents.

alkanolamines such as mono-, di- and triethanolamines andmonoisopropanolamine can also be used, by themselves or in combinationwith the alcohols. The phase stabilizers and/or co-solvents can, forexample, constitute 0 to 1 wt%, preferably 0.1 to 0.5 wt%, of thecomposition.

The compositions may optionally comprise components which adjust ormaintain the pH of the compositions at optimum levels. Examples of pHadjusting agents are NaOH and citric acid. The pH may be from, forexample, 1 to 13, such as 8 to 11 depending on the nature of thecomposition. For example, a dishwashing composition desirably has a pHof 8 to 11, a laundry composition has a pH of 7 to 9, and awater-softening composition has a pH of 7 to 9.

1. A process for producing a water-soluble container using a horizontalintermittent motion thermoforming machine which comprises the steps of:a) locating a first water-soluble film over a mould, said mouldcontaining a plurality of pocket forming cavities, defined by side wallsand a base, in a 2-dimensional array, each cavity being surrounded by aplanar surface of the mould on all sides in which the shortest dimensionof the planar surface between two adjacent cavities is at least 3 mm andbetween an edge of the mould and the closest cavity is at least 1.5 mm;b) thermoforming the first film to produce a plurality of pockets; c) atleast partially filling the pockets with a composition; and d) sealingthe plurality of the at least partially filled pockets, wherein thecavities are positioned in the array such that there are a plurality ofcontinuous strips of uninterrupted planar surface of the mould from aleading to a trailing edge of the mould, for receiving support meansfitted to the machine for supporting the film.
 2. A process as claimedin claim 1 in which step d) comprises placing a second water-solublefilm on top of the at least partially filled pockets and sealing thefilms together.
 3. A process as claimed in any one of the preceding


4. A process as claimed in any one of the preceding claims in which thedepth of the cavities lies in the range of 10 to 80% of the shortestdimension of the mouth cavity.
 5. A process as claimed in any one of thepreceding claims in which the depth of the cavities lies in the range of40 to 60% of the shortest dimension of the mouth cavity.
 6. A process asclaimed in any one of the preceding claims in which the cavity bases areplanar.
 7. A process as claimed in any one of claims 1 to 4 in which thecavity bases are rounded.
 8. A process as claimed in claim 6 in whichthe rounded bases have a radius of 20 mm.
 9. A process as claimed in anyone of the preceding claims in which corners formed where the cavityside walls meet each other are rounded.
 10. A process as claimed inclaim 9 in which the side wall corners have a radius of 10 mm.
 11. Aprocess as claimed in any one of the preceding claims in which edgesformed where the cavity side walls meet an upper surface of the mouldare rounded.
 12. A process as claimed in claim 11 in which the sidewall-mould upper surface edges have a radius of lmm.
 13. A process asclaimed in any one of the preceding claims in which bottom corners,formed where the cavity side walls meet the cavity base, are rounded.

side wall-base bottom corners have a radius of 10 mm.
 15. A process asclaimed in claim 13 or claim 14 in which air bores are located in theside wall base bottom corners.
 16. A process as claimed in claim 15 inwhich the air bores have a diameter of 0.1 mm to 1 mm.
 17. A process asclaimed in claim 16 in which the air bores have a diameter of 0.4 mm to0.5 mm.
 18. A process as claimed in any one of the preceding claims inwhich the shortest dimension of the planar surface between two adjacentcavities lies in the range of 4 mm to 10 mm and between an edge of themould and the closest cavity lies in the range of 2 mm to 5 mm.
 19. Aprocess as claimed in any one of the preceding claims in which acontinuous strip of uninterrupted planar surface is provided betweenadjacent rows of cavities.
 20. A process as claimed in any one of thepreceding claims in which a continuous strip of uninterrupted planarsurface is provided between every other pair of adjacent rows ofcavities.
 21. A mould for use in a thermoforming process formanufacturing water-soluble containers from water-soluble films, inwhich said mould contains a plurality of pocket forming cavities,defined by side walls and a base, in a 2-dimensional array, each cavitybeing surrounded by a planar surface of the mould on all sides in whichthe shortest dimension of the planar surface between two adjacentcavities is at least 3mm and between an edge of the mould and theclosest cavity is at least 1.5 mm, and

uninterrupted planar surface of the mould from a leading to a trailingedge of the mould.
 22. A mould as claimed in claim 21 in which the depthof the cavities lies in the range of 10 to 80% of the shortest dimensionof the cavity mouth.
 23. A mould as claimed in claim 21 or 22 in whichthe depth of the cavities lies in the range of 40 to 60% of the shortestdimension of the cavity mouth.
 24. A mould as claimed in any one ofclaims 21 to 23 in which the cavity bases are planar.
 25. A mould asclaimed in any one of claims 21 to 24 in which the cavity bases arerounded.
 26. A mould as claimed in claim 25 in which the rounded baseshave a radius of 20mm.
 27. A mould as claimed in any one of claims 21 to26 in which corners formed where the cavity side walls meet each otherare rounded.
 28. A mould as claimed in claim 27 in which the side wallcorners have a radius of 10 mm.
 29. A mould as claimed in any one ofclaims 21 to 28 in which edges formed where the cavity side walls meetan upper surface of the mould are rounded.
 30. A mould as claimed inclaim 29 in which the side wall-mould upper surface edges have a radiusof lmm.
 31. A mould as claimed in any one of claims 21 to 30 in whichbottom corners, formed where the cavity side walls meet the cavity base,are rounded.
 32. A mould as claimed in claim 31 in which the sidewall-base bottom corners have a radius of 10 mm.
 33. A mould as claimedin claim 31 or claim 32 in which air bores are located in the side wallsbase bottom corners.
 34. A mould as claimed in claim 33 in which the airbores have a diameter of 0.1 mm to 1 mm.
 35. A mould as claimed in claim34 in which the air bores have a diameter of 0.4 mm to 0.5 mm.
 36. Amould as claimed in any one of claims 21 to 35 in which the shortestdimension of the planar surface between two adjacent cavities lies inthe range of 4mm to lOmm and between an edge of the mould and theclosest cavity lies in the range of 2 mm to 5 mm.
 37. A mould as claimedin any one of claims 21 to 36 in which a continuous strip ofuninterrupted planar surface is provided between adjacent rows ofcavities.
 38. A mould as claimed in any one of claims 21 to 37 in whicha continuous strip of uninterrupted planar surface is provided betweenevery other pair of adjacent rows of cavities.
 39. A mould as claimed inany one of claims 21 to 38 in which air bores are lacated.
 40. Acontainer formed by the process of any one of the preceding claims.